[soong] new field in Android.bp to request APK signing V4

If "v4_signature: true" is set, the v4 signature file,
named [outputApkFile].idsig
will be generated along side the outputApkFile.

Test: m nothing
Test: atest PackageManagerShellCommandIncrementalTest
BUG: 149354175
Change-Id: Ie84725a15406f96f65042ea9909460e4eb34d57f
Merged-In: Ie84725a15406f96f65042ea9909460e4eb34d57f
diff --git a/java/java.go b/java/java.go
index 0188cf1..8ce982e 100644
--- a/java/java.go
+++ b/java/java.go
@@ -325,6 +325,10 @@
 
 	UncompressDex bool `blueprint:"mutated"`
 	IsSDKLibrary  bool `blueprint:"mutated"`
+
+	// If true, generate the signature file of APK Signing Scheme V4, along side the signed APK file.
+	// Defaults to false.
+	V4_signature *bool
 }
 
 func (me *CompilerDeviceProperties) EffectiveOptimizeEnabled() bool {